How to install and configure a fingerprint scanner on Xiaomi Redmi

The Xiaomi Redmi fingerprint scanner is not just a convenient way to unlock, but also an additional layer of security. However, many users face problems when first set up: the sensor does not recognize fingerprints, the system gives errors, or the feature is not on the menu at all. In this article, we will discuss all the steps of installing the scanner, from checking hardware compatibility to fine-tuning the sensitivity, and also tell you what to do if the sensor stops working after the MIUI update.

The Redmi series (including Note, POCO and numerical models like Redmi 12) is different in its sensor types: side (power button), subscreen optical and ultrasonic. The sensor type is not only the setting process but also the possible pitfalls. For example, underscreen scanners require more careful calibration, and side scanners can conflict with cases. We have taken into account all the nuances to ensure that your sensor works without failure.

1. Compatibility check: Is there a scanner in your Redmi model

Before you try to set up the sensor, make sure it's physically present on your device.Some low-end Redmi models (like the Redmi A1 or Redmi 9A) were released without a fingerprint scanner, even if it's listed in the specs on some sites.

• 🔍 Visual inspection: there should be a round/oval sensor on the back (under the camera) or on the side (in the power button.
• 📱 Characteristics of the MIUI: Go to Settings. → The phone. → Full specifications. The "Security" section should mention "Fingerprint sensor».
• 🔧 Check through ADB: Connect your phone to your PC and execute the command: adb shell dumpsys fingerprint If you have a sensor, you will see information about its status (mSensorPresent: true).

If the scanner is not in specs, but you are sure that it should be (for example, according to the official website of Xiaomi), it is possible that your device is a fake or a “gray” import with a stripped-down configuration.

⚠️ Note: On the Redmi Note 11 Pro+ 5G and POCO F4 GT The fingerprint scanner is built into the display, but only activates after the first update MIUI. If you bought a phone “with hands”, make sure that the firmware is original.

2. Prepare the phone before setting up the scanner

To avoid mistakes when adding fingerprints, follow the preliminary steps:

• 🧼 Clean the sensor: wipe the sensor with an alcohol wipe (for side scanners) or soft cloth (for underscreens.
• 🔋 Charge your phone: battery level should be at least 30%. MIUI may interrupt the adjustment process.
• 📵 Remove the case: even thin silicone cases can block side scanners. Underscreen sensors are less sensitive to this, but it's better to remove the protection.
• 👆 Update. MIUI: Go to Settings. → The phone. → System update: Outdated firmware versions often contain sensor bugs.

If you use screen film, make sure it doesn't cover the scanner area (relevant to the Redmi K50 and later), optical sensors don't work well through matte or thick film, and in extreme cases, you have to cut a hole above the sensor.

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If the scanner has been working before but suddenly stopped recognizing fingerprints, try resetting it: Settings → Passwords and Security → Fingerprint Sensor → Delete all fingerprints. After that, add the fingerprint again.

3. Step-by-step instruction: adding a fingerprint

The scanner setup process is the same for most Redmi models, but there are nuances for subscreen sensors.

1. Open security settings: Go to Settings → Passwords & Security → Fingerprint Sensor. If there is no point, then the sensor is not recognized by the system (see section 1).
2. Set a graphical/digital password: MIUI requires a backup unlock method. Come up with a strong PIN or a graphical key (at least 6 points).
3. Start scanning: Press Add Fingerprint and follow the screen cues. For side scanners, apply your finger at 45°, for underscreen, press the pad tightly.
4. Cover the entire surface of your finger: The system will ask you to raise and put your finger again to grab the edges. Take your time - the quality of the scan depends on this step.
5. Save your fingerprint: After a successful addition, assign it a name (for example, “Indicative Right”) and select the unlock functions: lock screen, payment confirmation, access to hidden folders.

For subscreen scanners (Redmi K40, POCO F3 and later), there is an additional step: after adding a fingerprint, the system will suggest calibrating sensitivity. Follow the instructions on the screen - this will improve recognition in bright sun or with wet fingers.

All covers and films removed.|Screen and sensor clean|Charge level >30%|Standby established PIN/password|Updated firmware MIUI-->

4. Configure additional scanner functions

The Xiaomi Redmi fingerprint scanner can do more than unlock the phone, and depending on the model, the following options are available:

To activate these functions:

1. Go to Settings → Passwords and Security → Fingerprint Sensor.
2. Select the added print and click "Functions of the fingerprint".
3. Check the boxes for the options you need. NFC-Payments will need to be pre-set up by Google Pay or Mi Pay.

Important: Some banking applications (e.g. Sberbank Online) require that the fingerprint be added after you install the application. If you added the fingerprint earlier, delete it and recreate it.

5. Common mistakes and their solutions

If the scanner is not working or if it gives an error such as “I could not add a fingerprint”, use this table:

If the problem persists, try resetting the security settings:

1. Go to Settings → Passwords and Security → Privacy settings.
2. Select “Reset security settings.”
3. After restarting, add the print again.

⚠️ Note: On the Redmi Note 9 Pro and POCO X3 NFC After the safety reset, the face unlock function may disappear.

6. Improved accuracy of recognition

If the scanner works but often gets it wrong, use these tips:

• 🔄 Add the same finger twice: register your index finger at different angles (e.g., "Indicator Right" and "Indicator Right Side"). This will increase your chances of recognition.
• 🌡️ Adjust the sensitivity: in Settings → Passwords and security → Fingerprint sensor → Include the option “High sensitivity” (not available on all models).
• 📱 Use alternative methods: If the scanner fails in the cold, add face unlock as a backup option.
• 🔋 Check the temperature of the phone: when overheating (for example, during games), the sensor can temporarily shut down.

For subscreen scanners (Redmi K50 Pro, POCO F5), there is a hidden setting that improves performance in bright sun:

1. Activate Developer Mode (7 times click on Version) MIUI» In Settings → The phone).
2. Go to Settings → Additional → For developers.
3. Find the option “Improving fingerprint recognition in bright light” and turn it on.

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If the scanner stopped working after the screen was replaced, 90 percent of the problem is caused by damage to the sensor plume, and underscreen sensors are particularly sensitive to poor-quality repair.

7. Hardware malfunctions: when to carry in the service

If none of these things worked, there may be a physical breakdown in the sensor.

• 🚨 The sensor does not respond to any touch (not even vibration when touched).
• 🔌 The phone does not see the scanner in adb shell dumpsys fingerprint (mSensorPresent: false).
• 💥 The scanner worked but stopped after falling or getting moisture.
• 🔄 The sensor recognizes fingerprints only at a certain angle (symptom of a disconnected plume).

The cost of repair depends on the type of sensor:

Before the service visit:

1. Make a backup of the data through Settings → About Phone → Backup.
2. Remove all fingerprints in the security settings.
3. Check if the warranty is valid (even if the phone is used, sometimes it goes over).

⚠️ Note: On the Redmi Note 12 Pro+ And the newer subscreen sensor is integrated into the display module, and replacing it requires a complete disassembly of the phone and costs up to 10,000 dollars. ₽.

FAQ: Frequent questions about the fingerprint scanner on Redmi